<?php
class Cookie{

	const AUTH_KEY = "asdgadfjh2kjajsldfaslkl";

	public function getCookie($name){

		if( null === $name )
			return "";

		return isset($_COOKIE[$name]) ? rawurldecode($_COOKIE[$name]) : "";

	}

	public function setCookie($name, $value, $expiry = 0, $domain=".", $httponly = 0, $secure = 0){
		if( trim($name) && trim($value) ){
			setcookie($name, $value, $expiry, '/', $domain, $secure, $httponly);
		}
	}

	/**
	 * user cookie hash
	 */
	public function authHash( $email, $password, $key, $expire=0){

		$data = $email;

		if($expire!=0)
			$data .= "|".$expire;

		$pass = substr($password, 0, 4);
		$data .= $pass;

		$ret = hash_hmac("md5", $data, $key);

		return $ret;
	}


	/**
	 * from discuz
	 * @supersession
	 */
	function authcode($string, $operation = 'DECODE', $expiry = 0) {

		$ckey_length = 4; // 随机密钥长度 取值 0-32;
		// 加入随机密钥，可以令密文无任何规律，即便是原文和密钥完全相同，加密结果也会每次不同，增大破解难度。
		// 取值越大，密文变动规律越大，密文变化 = 16 的 $ckey_length 次方
		// 当此值为 0 时，则不产生随机密钥
		$key = md5(self::AUTH_KEY);
		$keya = md5(substr($key, 0, 16));
		$keyb = md5(substr($key, 16, 16));
		$keyc = $ckey_length ? ($operation == 'DECODE' ? substr($string, 0, $ckey_length): substr(md5(microtime()), -$ckey_length)) : ''; 

		$cryptkey = $keya.md5($keya.$keyc);
		$key_length = strlen($cryptkey);

		$string = $operation == 'DECODE' ? base64_decode(substr($string, $ckey_length)) : sprintf('%010d', $expiry ? $expiry + time() : 0).substr(md5($string.$keyb), 0, 16).$string;
		$string_length = strlen($string);

		$result = ''; 
		$box = range(0, 255);

		$rndkey = array();
		for($i = 0; $i <= 255; $i++) {
			$rndkey[$i] = ord($cryptkey[$i % $key_length]);
		}   

		for($j = $i = 0; $i < 256; $i++) {
			$j = ($j + $box[$i] + $rndkey[$i]) % 256;
			$tmp = $box[$i];
			$box[$i] = $box[$j];
			$box[$j] = $tmp;
		}   

		for($a = $j = $i = 0; $i < $string_length; $i++) {
			$a = ($a + 1) % 256;
			$j = ($j + $box[$a]) % 256;
			$tmp = $box[$a];
			$box[$a] = $box[$j];
			$box[$j] = $tmp;
			$result .= chr(ord($string[$i]) ^ ($box[($box[$a] + $box[$j]) % 256]));
		}   

		if($operation == 'DECODE') {
			if((substr($result, 0, 10) == 0 || substr($result, 0, 10) - time() > 0) && substr($result, 10, 16) == substr(md5(substr($result, 26).$keyb), 0, 16)) {
				return substr($result, 26);
			} else {
				return ''; 
			}   
		} else {
			return $keyc.str_replace('=', '', base64_encode($result));
		}   

	}
}
